Cross section balancing and its applications in Petroleum Industry

Avinash Gupta
Department of Earth Sciences, IIT Roorkee

The construction of accurate geological cross sections is of the greatest importance to all branches of geology but is of paramount importance when large commercial investments are at stake. For this reason balanced section techniques have evoked considerable interest, in particular in areas of Overthrusting.

“A balance cross section is a geometrically correct (i.e. admissible) deformed- state cross section, which can be restored (i.e. viable) to an undeformed state or to an earlier less deformed state through kinematically valid steps.”

The technique involves simple steps of section construction using the surface and subsurface data (geological as well as geophysical), section balancing and restoration by appropriate method (equal line length method or equal area method or key bed method).

The technique of balancing cross-sections is an important method for studying the tectonic history of sedimentary basins. It enables one to compile charts for petroleum exploration and development, and growth sections of ancient structures can be restored so that the structural growth history can be studied.

The application of the technique of balanced section construction initially developed for areas of compressional folding and faulting but now days it is also applicable to regions of extentional tectonics and rift basins. This technique permits an understanding of the geometric and kinematic evolution of fault (and fold) structures as well as indicating the sequences of faulting and activity on faults.

The application of these methods aids seismic interpretation, indicates pathways of hydrocarbon migration and locations of entrapment, and constrains structural and Stratigraphic histories of sedimentary basin.

Presentation GEO India Expo XXI, Noida, New Delhi, India 2008©AAPG Search and Discovery